Coil form

ABSTRACT

A double-flanged coil form with a hollow core part is provided with an uninterrupted slot running through the core part in axial direction and through the flanges in the radial direction. The slot is as broad as the diameter or the breadth of the core part. The coil form can be die-cast or molded as a whole, avoiding the use of slides and a put-in core.

United States Patent Hultgren ..336/198 X Rolf Mar. 7, 1972 [54] COILFORM 3,019,375 1/1962 Geyer et al ..336/208 X 3,112,898 12/1963 Stahl...336/198 X I [72] Invent Numberg' Germany 3,218,592 11/1965 Banrick..336/208 x 73 A :It ti lStaddElectriC l 1 'j ffmfii' c FOREIGN PATENTSOR APPLICATIONS F 3 97 932,732 9/1955 Germany ..336/198 [22] ed eh 025,339 7/1956 Germany ..336/208 [21] Appl. No.: 8,363 Y PrimaryExaminen-Thomas J Kozma AttorneyC. Cornell Remsen, .lr., Walter J. Baum,Percy P. [30] Foreign Application Monty Data Lantzy, J. Warren Whitesel,Delbert P. Warner and James B.

Feb. 26, 1969 Germany ..G 69 07 606 Raden [52] US. Cl ..336/208 [57]ABSTRACT f A double-flanged coil form with a hollow core part isprovided with an uninterrupted slot running through the core part inaxial direction and through the flanges in the radial direction. [56]References Clted The slot is as broad as the diameter or the breadth ofthe core UNITED STATES PATENTS part. The coil form can be die-cast ormolded as a whole,

avoiding the use of slides and a put-in core. 708,220 9/ 1902 Gill..336/208 X 1 Claim, 1 Drawing Figure PATENTEDMAR "/1912 3,648,208

INVENTOR Helmut Rolf ATTORNEY COIL FORM The present invention relates toa coil form made from a die-cast or molded compound, and includes ahollow core part and two end flanges extending vertically in relation tothe coil axis. Such types of coil forms are required, for example, forrelay coils used in telecommunication and telephone systems, as well asin other communications systems, and in controlling, measuring andregulating arrangements.

In the known prior art the hollow core part serves to receive an ironcore or else one or more protective tubes of reed relays. The hollowcore part, therefore, just like each of the end flanges, may be shapedin accordance with the purpose of practical use of the coil form. Thus,for example, there are known cylindrical types of coil forms in whichthe hollow core part is a hollow cylinder, and in which the end flangesconsist of rings. Moreover, there are known coil forms having a squareshape, in which the hollow core part consists of a square box, and inwhich the end flanges are formed by square frames.

in cases where the known coil forms are intended to be manufactured asdie-cast or molded parts, the latter must be designed in such a way thatthe removal from the mold will not cause any difficulties. inconventional types of coil forms there are provided undercut portions,extending rectangularly in relation to the mold removal direction, byarranging laterally movable mold elements which are actuated prior tothe opening of the planes of the molds. in order to avoid the use ofmolds with sideway drawers or slides, coil forms are often composed ofhalves of identical shape (German Pat. application No. P 25 339Ville/21g). The known type of method, however, does not provide thepossibility of manufacturing coil forms quickly and inexpensively asdie-cast or molded parts.

The present innovation is based on the problem of providing a coil formwhich, by avoiding slider molds, and, if so required, an inserted orput-in type core, can be die-cast or molded as a whole. In the case of acoil form made from a diecast or compression molding compound,consisting of a hollow core part and two end flanges extendingvertically in relation to the coil axis, this problem is solved inaccordance with the present innovation, in that the coil form, in themanner known per se, comprises an uninterrupted slot extending in theaxial direction through the core part and, in the radial direction,through the flanges, and in that the slot in the core part is at leastas wide as the diameter thereof or the largest width thereofrespectively.

So-called double flanged coil forms comprising a hollow core part andslotted end flanges are known per se (German Auslegeschrift (DAS) 1 I09268). in the known case, however, there is concerned an uninterruptednarrow slot extending in both the core part and the flanges, serving toavoid the occurrence of eddy currents when using a coil form ofmagnetizable sheet metal. Such types of coil forms, however, cannot bemanufactured by using a sideway slideless die-cast or compression mold.

in distinction thereto, the present innovation provides a coil fonn inwhich the end flanges which hitherto formed a more or less closed ringor frame, and in which the core part comprises wide slots or recesses ina regular arrangement of such a type that the slots or recesses are atleast just as wide as the diameter or the largest width of the core partrespectively. in this way the coil forms may be removed from the moldeither in the axial direction or in the radial direction which is moreadvantageous owing to the short path of removal from the mold, withoutrequiring the use of sideway drawers or slides and a special core.Accordingly, the expensive slider molds which are susceptible tointerferences, and which were necessary hitherto, may be replaced bymore inexpensive slideless molds operating more precisely and reliably.in this way there is also safeguarded a more simple construction of thenecessary multiple molds. Coil forms according to the present innovationmay thus be manufactured in a substantially more rapid succession andmore inexpensively than in the conventional cases.

Moreover, coil forms according to the innovation, by maintaining theembodiment and the arrangement of the slots, may have any arbitraryshape which, above all, is dependent upon whether the hollow core partserves as an airgap, for receiving an iron core of certain shape, or oneor more protective tubes of reed relays. It may preferably be ofcylindrical, but also of a square shape. If the coil form, for example,forms part of a reed relay comprising a protective tube positionedwithin the hollow core part, a cylindrical coil form will be moreadvantageous for spatial reasons, than a square one, especially sincealso a hollow cylinder is more torsion-proof than a square box. If,however, several protective tubes lying next to each other are supposedto be supported inside the hollow core part, it will be generallypreferred to use the square shape because it safeguards a smallerbuild-in volume with a lower overall height.

As regards the manufacture of the die-cast or compression mold it is ofadvantage when the slot in the core part is in alignment with the slotsin the flanges. For example, if the core part forms a hollowsemicylinder, each flange comprises a correspondingly designed U-shapedrecess which is not closed on the side neighboring the open side of thecore part.

Moreover, it is of advantage to the outer circumferential surface of theend flanges to be designed at least on one side, in particular on theside neighboring the closed side of the core part, to have the shape ofa plane supporting surface. This substantially facilitates theinstallation of the coil form in a printed circuit.

Likewise under the aspect of an economical production, the coil formsmay either be die-cast from thermoplastic materials orcompression-molded from thermosetting plastics.

Further advantages and details of the innovation will now be explainedwith reference to the copending drawing from which there may be takenone particularly advantageous example of an embodiment relating to theinnovation. The single drawing shows in a perspective representation onecoil form according to the innovation.

The shown coil form consists of the hollow core part I, and of two endflanges 2,3 extending vertically in relation to the coil axis. Since inthe preferred example of embodiment of the innovation, the coil form hasa cylindrical shape, the core part 1 forms a hollow semicylinder,whereas the two end flanges 2,3 are designed as U-shaped frames, whichare not closed on the side neighboring the open side of the core part.For this reason, both end flanges 2,3 are provided with U-shaped slots2' or 3' respectively, extending in the radial direction. The widths ofthe slots 2',3' are chosen thus that they, on one hand, are in alignmentwith the slot provided in the core part 1 and, on the other hand, thattheir widths are at least just as large as the diameter of the hollowsemicylinder. The outer circumferential area of the end flanges 2,3, onthe side neighboring the closed side of the core part 1, is designed asan even supporting surface 2", 3".

From the enclosed drawing it may be taken that the outer circumferentialarea of the end ,flanges 2,3 is preferably designed to have a squareshape. The end flanges 2,3, together with the hollow core part 1, i.e.,half the hollow cylinder, form a winding body for electrical coils,whereas the hollow space 1 may serve, for example, to receive one ormore not shown protective tubes, as is known per se.

Moreover, it may be taken from the drawing that the slots 2', 3 and theslot (hollow space 1') in the core part 1 are designed to have equalshapes. in this way it is possible for the corresponding die-cast orcompression mold. to be manufactured in a more simple and, consequently,more economical way.

What is claimed is:

l. A coil form made from a single piece of molding compound, comprisinga one-piece hollow core in the form of a hollow cylinder terminating inopen ends, an uninterrupted slot extending along the length of thehollow cylinder parallel to a longitudinal axis and interconnecting theopen ends, an end flange at each end of the hollow cylinder integral tothe hollow cylinder and extending vertically to the longitudinal theflanges and being substantially in alignment with each of those slots toform a continuous slot along one side of the coil form, the flangesproviding plane supporting surfaces around the cylinder at the ends ofthe hollow cylinder.

1. A coil form made from a single piece of molding compound, comprisinga one-piece hollow core in the form of a hollow cylinder terminating inopen ends, an uninterrupted slot extending along the length of thehollow cylinder parallel to a longitudinal axis and interconnecting theopen ends, an end flange at each end of the hollow cylinder integral tothe hollow cylinder and extending vertically to the longitudinal axis ofthe cylinder from an open end of the cylinder, each of said flangesextending substantially an equal distance in each direction from theopen end of the cylinder, a slot extending radially through each of theflanges, the slot in the cylinder having a width substantially equal tothat of the slot in each of the flanges and being substantially inalignment with each of those slots to form a continuous slot along oneside of the coil form, the flanges providing plane supporting surfacesaround the cylinder at the ends of the hollow cylinder.